In some cluster systems, a plurality of nodes of the cluster may be connected to upstream routers or switches. In some embodiments, through the use of link aggregation, the nodes may appear to the upstream router to be a single device with multiple connections. The router may send packets down different connections to the individual devices of the cluster, which may then steer or distribute the packets to processing nodes as necessary, such as via a common data back plane.
Some packets may need to be sent to all devices of the cluster or all nodes connected to the router, such as multicast routing packets. However, in many embodiments, due to the link aggregation making it appear to the router that the cluster is a single device, the router may transmit a multicast routing packet only via one connection to one corresponding node. The recipient node may re-distribute the packet via the back plane, but if other nodes cannot distinguish between a re-distributed packet and the original multicast routing packet, they may themselves re-distribute the packet via the back plane, resulting in looping, excess bandwidth consumption, and interface muting.